Trade names provided by the University of Missouri Extension Service. For additional information, contact your local University Extension office.

Limitations

Do not apply these pesticides within 20 yards (ground application) or within 100 yards (aerial application) of the edge of caverns, sinkholes, and surface waters. Pesticide use limitations only apply at specific site locations within the shaded area(s) shown on the map. Contact the U.S. Fish and Wildlife Service at 573-876-1911 to determine if these pesticide use limitations apply to your site within the shaded area(s). (If a pesticide management plan has been developed for your property, the conditions of the plan take precedence over the pesticide use limitations described in this bulletin.)

Ozark cavefish [Amblyopsis rosae]

The Ozark cavefish is a true cave-dwelling species in all of its features. It is a tiny fish, growing only to 5 centimeters (2 in) in length. It has an elongated, flattened head, and a projecting lower jaw. It is an albino fish, with its body nearly devoid of any pigment. The fins of this cavefish are locked far back on its body. Due to the darkness of its habitat, the fish has only a trace of where its eyes are located, relying instead on hair-like sensory structures on its tail fin to feel its way through its environment.

The Ozark cavefish is a mysterious creature which is rarely seen. Little is known about its behavior or life history. This fish makes its home in the caves of the limestone formations of the Ozark Mountains. This cave habitat is fragile, offering little diversity or quantity in terms of food supply. For example, when inhabiting caves occupied by the endangered Gray Bat, Ozark cavefish use bat droppings as their primary source of energy.

The historic distribution of this threatened cavefish is largely unkown. It is the only cavefish within the Springfield Plateau of southwest Missouri, northwest Arkansas, and northeast Oklahoma. Currently, the cavefish lives in at least 29 caves of these three states. Although still occurring throughout much of its historic range, the frequency of cavefish sightings is decreasing. On average, one is able to see about five fish at each population site. The existing Ozark cavefish population is highly localized; nearly two-thirds of the known individuals are thought to inhabit a single cave in Arkansas, where up to 100 fish have been observed in one area.

The decline of the Ozark cavefish may be due to degradation of subsurface water, possibly from sinkholes in the soluble limestone or from heavy agricultural use where animal waste seeps into the ground water or flows in from outside streams. Industrial and residential development has also caused water contamination, leaking toxic levels of nickel from urban wastes into at least one cave system. Because of its low reproduction rate and confined habitat, the Ozark cavefish is vulnerable to even casual collecting. For example, it is thought that a scientific collection in the 1930's may be responsible for the very low population of cavefish in one Arkansas cave. Amateur spelunkers also pose a threat to the fragile habitat of this species.

The recovery of the Ozark cavefish seems to rely on public protection of its cave habitats. Arkansas now owns the cave with the largest known population of the cavefish. Missouri purchased another cave which contains a small population of this fish, but has a considerable amount of habitat which may support a reintroduction effort.